Empirical optimization of an angled spoke paddling wheel with self-rotating mechanism.

The development of the maritime industry has led to a corresponding increase in maritime accidents. Maritime accidents are major events that are costly to recover and can cause casualties. Moreover, individuals who are brought to the scene for recovery or rescue are at risk. To tackle this issue, the wheel mechanism of a water rescue robot, i.e., the angled spoke paddling wheel (ASPW), has been studied. The purpose of this study is to optimize the paddle design parameters of the ASPW using the Taguchi method. Experiments are conducted by creating paddles with various combinations of design parameters using [Formula: see text]([Formula: see text]) orthogonal arrays. The objective function is determining the optimal combination of paddle design parameters that will produce the greatest thrust force at the same RPM. Sensitivity analysis of each design parameter is conducted by calculating the signal-to-noise ratio from the experimental results. The pitch angle is found to be the most sensitive parameter. An additional experiment is conducted based on the results of the sensitivity analysis. The results show that the optimal design parameters are a pitch angle of [Formula: see text], rectangular end shape, X-axis curvature of 37.5 mm, and Y-axis curvature of 25 mm. The paddle with this combination of design parameters have a maximum thrust force of 64.74 gf at 120 RPM and exhibit up to an 18.27% improvement in performance compared with the initial paddle before optimization.

Design optimization of a linkage-based 2-DOF wheel mechanism for stable step climbing.

This paper presents the design optimization of a linkage-based wheel mechanism with two degrees of freedom, for stable step climbing. The mechanism has seven rotational joints and one prismatic joint. Kinematic and dynamic analyses of the mechanism were performed. The design was optimized in terms of linkage length and architecture to better manipulate the mechanism in its workspace, which was defined here by the targeted step size, as well as to ensure stability while climbing stairs. Optimization by genetic algorithm was performed using MATLAB. The optimized mechanism exhibited enhanced torque transmission from the input torque to the exerted for at the lobe of the wheel. Compliance control of the transformation will be addressed in the future.